and studying siblings would be much better. Hence, investigating twins who share an even greater genetic similarity than average siblings, should be very informative. If crime is an inherited trait, then the twins should exhibit quite a similar behavior. Environment interferes once again, since twins are generally brought up in the same house and share common life experiences. So that this is avoided the researchers divide the study of twins into two categories, one consisting of identical monozygotic twins and one consisting of fraternal dizygotic twins (Siegel & Senna 97). Monozygotic twins share an identical genetic makeup, while dizygotic twins share only 50% of their genetic combinations (Siegel & Senna 97). Based on this we could assume that if one of the identical monozygotic twins had a predisposition toward violent behavior, then his twin would likely have the same predisposition. Whereas if one of the fraternal dizygotic twins was violent then it is likely that his twin would have violent tendencies, although the chances would be sl
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